CN110050189A - The method of the concentration of the volatile organic compounds in fluid for controlling fluid network - Google Patents

Abstract

The invention relates to a method for monitoring the concentration of organic compounds in a fluid (11) of a network, the fluid (11) containing volatile organic compounds, the method comprising the steps of: Measuring the fluid on-line by an analyzer (15) The first step of the concentration of each of the organic compounds in (11) (16), the concentration (16) of each organic compound measured by the analyzer (15) is compared with the pre-defined values for each organic compound A second step in which thresholds (160) are compared, if the concentration (16) of at least one organic compound measured by the analyzer (15) is greater than a corresponding predefined threshold (160) reducing the concentration of the at least one organic compound The third step of concentration. The invention also relates to a device (10) for monitoring the concentration of organic compounds.

Description

for controlling the concentration of volatile organic compounds in fluids of fluid networks method

The present invention is in the field of on-line measurement of organic compounds in fluid networks and relates to a method for monitoring the concentration of organic compounds in fluids of a fluid network. The invention also relates to a device for monitoring the concentration of organic compounds in a fluid of a fluid network. The invention can also be applied to monitor any type of fluid, whether it is cooled network water, natural, ambient or treated water, or gaseous fluids such as air. The present invention is applicable to volatile or non-volatile organic compounds.

Drinking water consists of dozens of non-specific parameters (temperature, pH, conductivity, turbidity, etc.), microbial parameters (E. coli, total bacteria, etc.), and organic chemical parameters (pesticides, hydrocarbons, chlorinated solvents, trihalomethanes, etc.) etc.) and inorganic chemical parameters (metals, bromates), etc. Compliance is monitored by means of sampling and laboratory analysis, the results of which can be known over time periods ranging from 12 hours to several weeks. Furthermore, for large facilities, the frequency of these analyses can vary from daily (microorganisms, at large facilities) to monthly best-case scenarios for organic and inorganic chemical parameters. For equipment transmitting less than 1000 ^m3 /day, this frequency may only be once a year. It is therefore clear that undetected inconsistencies may arise during the interval between these laboratory analyses and thus may not be able to take action at the processing device. An ideal solution may involve controlling the processing means with information provided daily or several times a day by continuous or semi-continuous measurement systems upstream and/or downstream of the processing.

Continuous measurement probes already exist for a limited number of simple physicochemical parameters such as pH, turbidity, conductivity, temperature, UV absorbance, but so far no processing equipment has been found capable of monitoring the concentration of organic compounds.

It therefore appears necessary to control or optimize treatment plants by means of information derived from on-line analysis of specific (individual) organic compounds, especially volatile organic compounds (VOCs). A VOC is defined in France (Decree No. 2006-623) as any organic compound having a boiling point less than or equal to 250° C. (see table below), measured at a standard pressure of 101.3 kPa. VOCs should be considered because they are toxic or produce odors and odors. Compounds of particular relevance for drinking water applications are those most frequently found in the resource, some of which are regulated (shown in bold in the following tables): vinyl chloride, 1,1-dichloroethane, ETBE , 1,1,1-trichloroethane, chloroform, cis-1,2-dichloroethylene, trichloroethylene and tetrachloroethylene:

But there are biases related to the complexity of laboratory chromatographs and the expertise required to use them.

The present invention aims to overcome all or some of the above-mentioned problems by providing a method for monitoring the concentration of organic compounds in the fluids of a fluid network by performing on-line measurements of organic compounds and the results of their measurements This makes it possible to control industrial processes in order to reduce this concentration of organic compounds if the concentration is too high. This method makes it possible to improve the actionable use of data derived from monitoring organic compounds of water networks. It ensures the same performance as the laboratory reference method (with a relatively low maximum allowable deviation) and thus enables the optimization of the process line without the risk of over- or under-dosing of the product aimed at reducing the concentration of organic compounds operational parameters.

To this end, a subject of the present invention is a method for monitoring the concentration of organic compounds in a fluid of a fluid network of an industrial plant, the fluid containing a plurality of organic compounds, characterized in that the method comprises the following steps:

a first step of measuring the concentration of each of the plurality of organic compounds in the fluid of the fluid network online by an analyzer,

a second step of comparing the concentration of each of the plurality of compounds measured by the analyzer to a predefined threshold for each organic compound, such as a treatment setpoint value or a maximum alarm value,

• A third step of reducing the concentration of the at least one organic compound if the concentration of the at least one organic compound measured by the analyzer is greater than a corresponding predefined threshold value.

According to one embodiment, the third step of reducing comprises the step of injecting a product having the effect of reducing the concentration of at least one organic compound into the fluid network. It can be the step of injecting reactants (eg, adsorption media, oxidant, stripping gas) into the fluid network or using a treatment method (eg, membrane filtration).

According to one embodiment, the industrial plant is intended to perform an industrial process, and reducing the third step comprises acting on at least one parameter in the industrial process which has the effect of reducing the concentration of said at least one organic compound.

According to another embodiment, the monitoring method according to the invention, before the third step of reducing, comprises the step of remotely transmitting the concentration of each of the plurality of organic compounds measured by the analyzer to a control center.

According to one embodiment, the industrial method is a method of treating a liquid fluid by aeration using a gaseous fluid in a predefined ratio between the liquid fluid and the gaseous fluid, and the third step of reducing comprises according to a measurement in the fluid of the network. The change in the concentration of the at least one volatile organic compound adjusts the ratio between the liquid fluid and the gaseous fluid.

According to another embodiment, the industrial method is a drilling method utilizing a drilling fluid, and the third step of reducing comprises adjusting the density and/or the density of the drilling fluid as a function of a change in the concentration of the at least one organic compound measured in the fluid of the network. or ingredients.

According to another embodiment, the industrial method is a method for sanitizing water by adding at least one oxidizing reactant, and the third step of reducing includes adjusting the concentration of at least one organic compound measured in the fluid of the network The amount of at least one reactant (eg, chlorine) added.

According to another embodiment, the industrial method is a method for treating drinking water, the industrial plant comprising at least one filter with a granular adsorption medium, such as activated carbon, or injecting a powdered medium, such as activated carbon, and reducing the third step Include the step of varying the flow rate of the fluid through the sorbent/fluid contactor, such as a filter with particulate sorbent media, or a powdered sorbent media/fluid divider. The metering of the powdered adsorption medium can also be adjusted according to the desired reduction of organic compounds and according to on-line monitoring.

Advantageously, the third step of lowering further comprises the step of regenerating the filter medium and the regeneration of the medium is performed at a fixed or variable frequency.

The industrial treatment process can also be a nanofiltration or reverse osmosis type of process based on hydrophilic membranes permeable to liquid fluids or hydrophobic membranes permeable to gaseous fluids.

The invention also relates to a device for monitoring the concentration of organic compounds in a fluid of a fluid network of industrial equipment suitable for performing an industrial process, the fluid containing a plurality of organic compounds, the device comprising: an analyzer positioned at a first location in the fluid network, adapted to measure online the concentration of each of the plurality of organic compounds in the fluid at the first location; a comparator adapted to measure the plurality of organic compounds to be measured by the analyzer the concentration of each of the organic compounds in the compound is compared to a predefined threshold for each organic compound; a correction unit adapted if the concentration of at least one of the plurality of organic compounds measured by the analyzer is greater than A corresponding predefined threshold reduces the concentration of the at least one organic compound in the fluid.

Advantageously, the correction unit comprises means for injecting into the fluid network a product having the effect of reducing the concentration of said at least one organic compound.

According to one embodiment, since the industrial process involves at least one parameter, the correction unit comprises a first control module configured to act on the industrial process as a function of the measured change in the concentration of the at least one organic compound has at least one parameter in the effect of reducing the concentration of the at least one organic compound.

According to another embodiment, the monitoring device comprises a remote transmission device adapted to remotely transmit the concentration of each of the plurality of organic compounds measured by the analyzer to a control center.

A better understanding of the invention and other advantages will become apparent on reading the detailed description of the embodiments, given by way of example, which is illustrated by the accompanying drawings, in which:

- Figure 1 schematically represents the steps of the method according to the invention for monitoring the concentration of organic compounds in the fluid of a network,

- Figure 2 schematically represents an embodiment of the device according to the invention for monitoring the concentration of organic compounds in the fluid of a network,

- Figure 3 schematically represents another embodiment of the device according to the invention for monitoring the concentration of organic compounds in the fluid of a network.

For the sake of clarity, identical elements will have the same reference numerals in the various figures.

Figure 1, with additional reference also to Figure 2, schematically represents the steps of a method according to the invention for monitoring the concentration of organic compounds in a fluid 11 of a network. The method is used to monitor the concentration of organic compounds in a fluid 11 of a fluid network of industrial equipment, the fluid 11 containing a plurality of organic compounds, the method comprising: measuring the plurality of organic compounds in the fluid 11 of the fluid network online by an analyzer 15 A first step 1001 of the concentration 16 of each organic compound in the multiplicity of organic compounds measured by the analyzer 15 compares the concentration 16 of each organic compound in a second step 1002 of comparing a fixed point value or a maximum alarm value) and reducing the concentration of at least one organic compound if the concentration 16 of the at least one organic compound measured by the analyzer 15 is greater than the corresponding predefined threshold 160 The third step 1003 of 16.

The analyzer 15 is configured for on-line measurement of the concentration 16 of each of the plurality of organic compounds present in the fluid 11 . This results in a number of concentrations 16, one for each organic compound measured. And for each organic compound, a threshold value 160 is predefined, each value may be different depending on the criteria in effect. Each concentration of the organic compound measured is compared to a threshold value corresponding to the organic compound under consideration. If the measured concentration of the organic compound is greater than the threshold, a corrective action corresponding to the third step 1003 is required for reducing the concentration of the organic compound.

The third step 1003 of reducing may in particular comprise the step 1004 of injecting a product having the effect of reducing the concentration of said at least one organic compound into the network of fluid 11 . The injection of the product may be subject to closed-loop control by the difference between the measured concentration and a predefined threshold of the concentration of the organic compound.

The monitoring method according to the present invention may comprise the step 1005 of remotely transmitting the concentration 16 of each of the plurality of organic compounds measured by the analyzer 15 to the control center of the processing device before the third step 1003 of reducing. The control center can then also act on the concentration of organic compounds, optionally by manual intervention.

A particularly advantageous aspect of the invention applies to an industrial plant 9 intended to perform the industrial method 1000 . According to the invention, reducing the third step 1003 comprises acting on at least one parameter 12 in the industrial process 1000 having the effect of reducing the concentration 16 of the at least one organic compound whose value measured by the analyzer 15 The concentration is greater than its predefined threshold 160.

The present invention thus makes it possible to control and optimize industrial processes (in terms of performance and operating costs) in the world of water and the environment through the on-line measurement of organic compound concentrations. For example, the present invention helps to improve treatment systems by preventing industrial pollution due to chlorinated solvents in water resources. By controlling the operational parameters of industrial equipment upstream, the present invention makes it possible to monitor by-products of chlorine disinfection, such as trihalomethanes, which are volatile organic compounds and are the subject of recommendations by the World Health Organization or have limit value. In the context of the present invention, it is also possible to identify and treat air pollution such as those produced by the wastewater industry and sludge treatment which generates olfactory pollutants.

According to one embodiment, the industrial method 1000 is a method for treating a liquid fluid by aeration with a gaseous fluid in a predefined ratio between the liquid fluid and the gaseous fluid, and the third step 1003 of reducing comprises according to the Changes in the measured concentration of at least one organic compound in the fluid adjust the ratio between the liquid and gaseous fluids. This leads to good monitoring of the efficiency of the treatment process (also known as stripping process) and optimization of its operating costs.

According to another embodiment, the industrial method is a drilling method utilizing a drilling fluid, and the third step 1003 of reducing comprises adjusting the density of the drilling fluid and/or the change in the concentration of at least one organic compound measured in the fluid of the network Element. In other words, the present invention achieves good monitoring of contaminated drilling fluids by utilizing a mixture of contaminated/uncontaminated drilling fluids in order to comply with regulations related to water distribution.

According to another embodiment, the industrial method is a method for sterilizing water by adding at least one reactant, and the third step 1003 of reducing comprises varying the concentration of at least one organic compound measured in the fluid of the network The amount of at least one reactant added is adjusted.

According to another embodiment, the industrial method is a method for the treatment of drinking water, the industrial plant comprising at least one filter with a granular adsorption medium such as granular activated carbon, or with injection of a powdered adsorption medium, or with activated carbon powder Contactor or Membrane Separation Method of Adsorbent Media in Form of a Contactor, and the third step of reducing 1003 includes the step of changing the flow rate of the fluid through the sorbent/fluid contactor, such as a filter with particulate sorbent material or media or a powdered sorbent media/ Fluid separators or in contactors with powdered adsorption media. The third step 1003 may also include the step of changing the metering of the powdered adsorption medium. That is, the metering of the powdered adsorption medium can also be adjusted according to the desired reduction of organic compounds and according to on-line monitoring.

In other words, the filter is located in the processing device. Drinking water treatment units often include activated carbon filters designed to eliminate micro-pollutants. Elimination of organic compounds can be improved by acting on the flow rate of water passing through such filters and the frequency of their regeneration. Reactors can also be used in the plant for contacting water/powdered adsorption media, such as powdered activated carbon, which are designed to eliminate micro-pollutants. Elimination of organic compounds can be improved by acting on the flow rate of water through such contactors and the metering of the powdered medium.

Advantageously, lowering the third step 1003 further comprises a step 1006 of regenerating the filter media and the regeneration of the media is performed at a fixed or variable frequency.

The industrial method (1000) may also be a method for treating drinking water, the industrial device comprising at least one hydrophilic membrane permeable to liquid fluids or at least one hydrophobic membrane permeable to gaseous fluids, or of the nanofiltration or reverse osmosis type . And in this case, reducing the third step 1003 includes the step of changing the flow rate of the fluid through the membrane.

After the measurement by the analyzer 15, if the adjustment value is exceeded, the results of the measurement performed online by the analyzer 15 are used for the operation of the industrial treatment plant by, for example, reducing the dosage of chlorine, or by acting on the coagulant. The amount or dosage of powdered activated carbon or the frequency of regeneration acting on the carbon filter optimizes the elimination of organic materials in feedback.

The implementation of the method according to the invention makes it possible to measure the concentration of organic compounds in the relevant fluids, as it is performed in-line and continuously or semi-continuously, with useful results in improving industrial processes associated with fluids.

The industrial process is controlled in real time, which makes it more responsive to any possible industrial pollution. Such real-time control is not conceivable in the case of fluid sampling for analyzing organic compound concentrations in the laboratory, due to the lengthy turnaround time. In addition, since organic compounds can be volatile organic compounds, there are measurement accuracy issues for laboratory analysis, as there is a high probability that volatile organic compounds are no longer present in the sample being analyzed. Therefore, the control of the industrial process according to the present invention makes it more relevant and closer to reality by actually capturing the pollutants and by treating them in an appropriate manner. The resulting advantages are savings in time, cost, and quality of fluid handling.

Figure 2 schematically represents an embodiment of a device 10 according to the invention for monitoring the concentration 16 of organic compounds in a fluid 11 of a network. Apparatus 10 for monitoring a concentration 16 of an organic compound in a fluid 11 of a network of fluids 11 of industrial equipment 9 suitable for performing industrial method 1000 includes an analyzer 15 positioned at a first location 13 in the fluid network , suitable for online measurement of the concentration 16 of each of the plurality of organic compounds in the fluid 11 at the first location 13 . The analyzer 15 is a type capable of continuous or semi-continuous on-line measurement of several organic compounds conditioned or normally present in water or any other relevant fluid. The monitoring device 10 comprises: a comparator 17 adapted to compare the concentration 16 of each of the plurality of organic compounds measured by the analyzer 15 with a predefined threshold 160 for each organic compound; and a correction unit 18. The correction unit is adapted to reduce the concentration 16 of at least one organic compound in the fluid 11 if the concentration of at least one organic compound of the plurality of organic compounds measured by the analyzer 15 is greater than a corresponding predefined threshold 160.

The analyzer 15 may, for example, be a portable gas chromatograph including a sampling device connected to a trace argon ionization detector. The analyzer 15 may include two probes, one being a temperature probe and the other allowing argon to enter the fluid. Two types of containers can be fastened to it. One is used for static testing and can have a 2L capacity. The second container is used for online analysis. It is equipped with two openings, one for the inlet of the fluid and the other for the outlet, which are connected to pipes to form a circuit. Advantageously, the analyzer 15 is activated as soon as it is connected to the current outlet. Data processing is carried out on a computer equipped with suitable software networked to the analyzer 15 . It must be connected to an argon cylinder for operation. On-line analyzers are able to operate continuously with as little maintenance as possible. Analysis can be performed without pre-treatment or pre-filtration of unreloaded water.

For water analysis, water is continuously circulated through the lower unit. At a programmable frequency, the organic compounds of the circulating water are stripped with an inert gas (argon in this case), transported by the argon gas through an adsorbent that traps them. The latter is then thermally desorbed and the organic compounds are transported by an argon carrier gas to a chromatographic column where they are physically separated. The isolated compounds are then detected by a micro-argon ion detector that requires argon for its operation. Such a system thus operates according to the dynamic headspace principle.

It should be noted that this is an example of an analyzer 15 that can be used in the context of the present invention. The present invention may be implemented using any type of analyzer capable of independently separating organic compounds on-line, continuously or semi-continuously, in order to determine their concentration.

Advantageously, the correction unit 18 may comprise means for injecting into the network of fluid 11 a product having the effect of reducing the concentration of said at least one organic compound.

According to another embodiment, the monitoring device 10 includes a remote transmission device adapted to remotely transmit the concentration 16 of each of the plurality of organic compounds measured by the analyzer to a control center.

Figure 3 schematically represents another embodiment of a device 10 according to the invention for monitoring the concentration of organic compounds in a fluid 11 of a network. The industrial method 1000 involves at least one parameter 12, and the calibration unit 18 includes a first control module configured to act in the industrial method 1000 to have a reduction in the at least one organic compound based on a change in the measured concentration of the at least one organic compound. At least one parameter 12 of the effect of the concentration of an organic compound.

Thus, such a monitoring device 10 according to the present invention makes it possible to obtain on-line measurements of the concentration of organic compounds in fluids, as well as to control industrial processes associated with fluids. More specifically, such monitoring devices make it possible to identify and deal with contamination by acting on the operating parameters of the industrial process in order to optimally adapt the operation of the industrial plant while taking into account the levels of organic compounds derived therefrom. As already mentioned, the organic compounds can be chlorinated solvents in water, trihalomethanes, but also additives especially dedicated to fuels, for example, ethyl tert-butyl ether (ETBE) or methyl tert-butyl ether (MTBE), or even odorous algal metabolites under conditions where the analyzer's detection threshold is sufficiently low. Of course, the present invention is applicable to any volatile organic compound.

Claims (14)

1. A method for monitoring the concentration of volatile organic compounds in a fluid (11) of a fluid network of an industrial plant (9), the fluid (11) comprising a plurality of volatile organic compounds, characterized in that the The method includes the following steps: a first step (1001): online measurement of the concentration (16) of each of the plurality of volatile organic compounds in the fluid (11) of the fluid network by an analyzer (15) , a second step (1002): comparing the concentration (16) of each volatile organic compound in the plurality of organic compounds measured by the analyzer (15) with a predefined value for each volatile organic compound Thresholds (160) such as process setpoint values or maximum alarm values are compared, a third step (1003): reducing said at least one volatile organic compound if said concentration (16) of said at least one volatile organic compound measured by said analyzer (15) is greater than a corresponding predefined threshold (160) the concentration of sexual organic compounds. 2. The monitoring method according to claim 1, characterized in that the third step (1003) of reducing comprises the step of injecting into the fluid network a product having the effect of reducing the concentration of the at least one volatile organic compound (1004). 3. The monitoring method according to any one of claims 1 and 2, the industrial plant (9) intended to implement an industrial method (1000), characterized in that the third step (1003) of reducing consists in acting on the at least one parameter (12) of the industrial process (1000) having the effect of reducing the concentration of the at least one volatile organic compound. 4. The monitoring method according to any one of the preceding claims, characterized in that the method comprises the plurality of volatiles to be measured by the analyzer (15) prior to the third step (1003) of reducing The step (1005) of remotely transmitting said concentration (16) of each volatile organic compound in the organic compound to a control center. 5. The monitoring method according to any one of claims 3 and 4, characterized in that the industrial method (1000) is a method of treating a liquid fluid by aeration with a gaseous fluid according to a predefined ratio between the liquid fluid and the gaseous fluid, and said third step (1003) of reducing consists in adjusting the ratio between liquid and gaseous fluids according to the concentration of said at least one volatile organic compound measured in the fluid of said network. 6. The monitoring method according to any one of claims 3 and 4, characterized in that the industrial method (1000) is a drilling method utilizing drilling fluid, - and the third step (1003) of reducing consists in adjusting the density and/or composition of the drilling fluid according to the concentration of the at least one volatile organic compound measured in the fluid of the network. 7. The monitoring method according to any one of claims 3 and 4, characterized in that the industrial method (9) is a method for sterilizing water by adding at least one reactant, - and the third step (1003) of reducing consists in adjusting the amount of the at least one reactant added according to the concentration of the at least one volatile organic compound measured in the fluid of the network. 8. The monitoring method according to any one of claims 3 and 4, characterized in that the industrial method (9) is a method for the treatment of drinking water, the industrial plant comprising at least one filter with a granular adsorption medium, or a contactor or a membrane separation method with an activated carbon powdered adsorption medium, and said reducing the third step (1003) comprises varying the flow rate of said fluid through said filter with particulate adsorption medium or the flow rate of said fluid in said contactor with powdered adsorption medium step, or include the step of changing the metering of the powdered adsorption medium. 9. The monitoring method according to claim 8, characterized in that said lowering third step (1003) further comprises a step (1006) of regenerating said filter medium and the regeneration of said filter medium is fixed or variable variable frequency. 10. The monitoring method according to any one of claims 3 and 4, wherein: the industrial method (9) is a method for treating drinking water, the industrial equipment comprising at least one hydrophilic membrane permeable to liquid fluids or at least one hydrophobic membrane permeable to gaseous fluids, - and said reducing the third step (1003) comprises the step of changing the flow rate of said fluid through said membrane. 11. A device (10) for monitoring the concentration of volatile organic compounds in a fluid (11) of a fluid network of an industrial plant (9) suitable for carrying out an industrial process (1000), the fluid (11) comprising A variety of volatile organic compounds, characterized in that the device comprises: an analyzer (15), located at a first location (13) in the fluid network, adapted to measure on-line the multiple in the fluid (11) at the first location (13) the concentration of each volatile organic compound in the volatile organic compounds (16), a comparator (17) adapted to compare the concentration (16) of each volatile organic compound in the plurality of organic compounds measured by the analyzer (15) with the concentration (16) for each volatile organic compound A predefined threshold (160) for organic compounds is compared, a correction unit (18) adapted if the concentration (16) of at least one volatile organic compound of the plurality of organic compounds measured by the analyzer (15) is greater than the corresponding predetermined Defining a threshold (160) reduces the concentration (16) of the at least one volatile organic compound in the fluid (11). 12. A monitoring device (10) according to claim 11, characterized in that the correction unit (18) comprises a device which will have the effect of reducing the concentration (16) of the at least one volatile organic compound The means by which product is injected into the fluid network. 13. The monitoring device (10) according to any one of claims 11 and 12, characterized in that the correction unit (18) comprises a first control module configured to act on the industrial At least one parameter (12) of the method (1000), the at least one parameter having reducing the concentration (16) of the at least one volatile organic compound as a function of a change in the measured concentration of the at least one volatile organic compound Effect. 14. Monitoring device (10) according to any one of claims 11 to 13, characterized in that it comprises a remote transmission device adapted to measure the polynomial measured by the analyzer (15) Said concentration (16) of each of the volatile organic compounds is transmitted remotely to a control center.